It's pretty difficult to be band if your guitarist dies. He (hide, the guitarist) died in 1998.

WIKIPEDIA
"Yoshiki and Hide were believed to have been secretly planning to resurrect X in 2000, sans Toshi, and were looking for a replacement singer. Tragedy rendered these plans impossible when Hide died in the hospital on May 2, 1998 after a night of hard drinking. He was found hung to a doorknob by a towel. This news stunned Japan's youth; four fans around the country attempted suicide, two of whom died. Much speculation about Hide's death has taken place, but no definitive explanation has been found. An apparent suicide, it is thought by some to be an accidental death, but there is not a clear motive for either suicide or murder. Some speculate that the lyrics to the song "Pink Spider" by Hide, which was set to be released the day after his death, is a suicide note of sorts. Following Hide's demise, Yoshiki entered a state of depression for almost three years, being unable to compose or play."

Ok, here are a few recommendations. I just randomly chose a few bands from my playlist and I tried to get a variety of bands [Jpop, Jrock, Jhip-hop]. Erm, this post might get a bit long. I'm so sorry if it does.

abingdon boys school
Members: TMR [vocals], SUNAO [guitar], Hiroshi Shibasaki [electric guitar], & Toshiyuki Kishi [keyboards]. There are also two support members Ikuo [bass] & Kozy Hasegawa [drums].
Description: I'm sure the majority of you are familiar with TMR. abingdon boys school formed in 2005 and currently only has seven songs, some of which you might be familiar with: stay away was featured on a NANA tribute album, Dress is a BUCK-TICK cover, & INNOCENT SORROW is in D.Gray-man. There's not much else to say about them, other than they're great.

AIRMAIL
Members: Tommy [vocals & guitar], Yamasaki [drums], Kan [guitar], Ono [guitar], & Izumi [bass].
Description: I uploaded an album of theirs at my rotation journal last year and people LOVED it. Whenever I upload their songs, people always tell me how much they love this band. I honestly have yet to hear anyone say anything bad about them. Their music is incredibly mellow. If you're a screamy/growly fan, this band isn't for you. Their songs are all very calm & soothing. They remind me so much of ART-SCHOOL. If you're an ART-SCHOOL fan, you'll love AIRMAIL. Also, quite a few of their songs are in English.

Catheline
Members: マモ [vocals], Z [guitar], 楓 [guitar], 七星 [bass], & Kaoru [drums].
Description: Growly fans, this band is for you! Actually, even if you aren't a fan of screamy bands, you still should definitely try them out. I absolutely HATE screamy bands, but I think this band is excellent. I think what makes Catheline different from other growly bands is the fact that the growling isn't random. I'm not really sure how to explain that, but you'll understand if you listen to them. I also like how マモ actually sings, rather than just growling throughout the entire song.

Furil
Members: Asuka [vocals] & Eiji [pretty much does everything else: plays all the instruments, sings the choruses, & writes the lyrics].
Description: I dare you to be in a grumpy mood while listening to them. You can't. It's impossible. I mentioned before that I cannot tolerate female singers, but Asuka's the exception. Her voice might not appeal to some of you though - it's the high, squeaky type of voice. Their music is just absolutely adorable. It's a blend of Jpop and electronic. ^^; They have a song called Hello Their! gllsdapfapgegs How cute is that?! ..also, Eiji is quite gorgeous. :D

ku-tyu-bunkai
Members: Hayato Kobayashi [vocals, bass, & absolutely beautiful], kentaroyd [guitar], & Shingo Wakaki [synth].
Description: LOVE. Absolute love. Ok, I'll admit that I'm a bit shallow. What originally drew me to this band was the fact that they have an insanely gorgeous singer. Their music is incredible. They're another band that I had featured at my rotation journal that everyone seems to love. They describe their sound as a mixture of Jpop, electronica, & techno. I think it's absolutely amazing. There's a song of theirs called ☆MANIARC★ that is the epitome of sex. *_* Mmm. So lovely. I highly recommend these guys.

L'yse:nore
Members: 水恋 [vocals], hisashi [guitar], 憂己 [synthguitar & guitar], 未散 [bass], & Tomoki [drums].
Description: L'yse:nore was a VK band from the late 90s. To be honest, when I first decided to listen to them, I really didn't have high expectations. I assumed that they'd either be really crappy or end up having that generic VK sound. I was wrong. Their music is beautiful.

MIG MARKET
Members: BISCO [MC], Tibic [MC], YOUZEE [MC], 2-KASA [DJ], Shingo [support member].
Description: Here's a band for the hip-hop fans. I would say their music is a bit more on the pop-ish side, but they're still a hip-hop band and even rap quite a bit. They're great & their songs are awesome.

I'll stop there for now. I had a much longer list, but I decided to just post these ones for now. However, if anyone wants to personally ask for a recommendation, I'd be more than happy to help out. Just let me know what kind of band/sound you're looking for, or maybe some other bands you're interested in and I'll do my best to pick out some bands you might enjoy.